High-Resolution X-Ray CT Scanning Reveals the First Resin-Embedded Miniature Gecko of the Ge

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Zeitschrift/Journal: Bonn zoological Bulletin - früher Bonner Zoologische Beiträge.

Jahr/Year: 2018

Band/Volume: 67

Autor(en)/Author(s): Daza Juan D., Hunziker Jordan P., Bauer Aaron M., Wagner Philipp, Böhme Wolfgang

Artikel/Article: Things are not always as they seem: High-resolution X-ray CT scanning reveals the first resin-embedded miniature gecko of the genus Ebenavia 71-77 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

Bonn zoological Bulletin 67 (2): 71–77 ISSN 2190–7307 2018 · Daza J.D. et al. http://www.zoologicalbulletin.de https://doi.org/10.20363/BZB-2018.67.2.071

Scientific note urn:lsid:zoobank.org:pub:AA5B7777-C36B-4E9C-B77E-272FBCBA3D7A Things are not always as they seem: High-resolution X-ray CT scanning reveals the first resin-embedded miniature gecko of the genusEbenavia

Juan D. Daza*, 1, Jordan P. Hunziker1, Aaron M. Bauer2, Philipp Wagner2, 3, Wolfgang Böhme4 1 Department of Biological Sciences, Sam Houston State University, 2000 Avenue I, Life Sciences Building, Room 105, Huntsville, TX 77341, USA 2 Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, PA 19085, USA 3 Allwetterzoo Münster, Sentruper Str. 315, D-48161 Münster, Germany 4 Zoologisches Forschungsmuseum A. Koenig, Adenauerallee 160, D-53113 Bonn, Germany * Corresponding author: E-mail: [email protected] 1 urn:lsid:zoobank.org:author:7F796C4B-B0D5-4669-8D6F-96CA494B62F5 2 urn:lsid:zoobank.org:author:A54A16B8-BEE1-4996-9170-6CADB539B5D1 3 urn:lsid:zoobank.org:author:0575CE45-AB5C-4493-A8AD-DD399E18284A 4 urn:lsid:zoobank.org:author:FFAC2972-9F52-404B-BA9C-489C7793FF8D * urn:lsid:zoobank.org:author:78BB0EB0-8A48-4A1D-8D53-287AD1EF5FFA

Abstract. We identify a presumed specimen of Sphaerodactylus in amber from the Zoological Research Museum Alexan- der Koenig as being embedded in copal, rather than amber. Further, the specimen matches the morphology not of a Hispa- niolan gecko, but of the extant Madagascan species Ebenavia boettgeri, which occurs in a known area of copal deposits. Key words. Sphaerodactylus, Ebenavia, CT scan, Madagascar, Osteology.

Fossil lizards embedded in amber are frequently spec- (1998). The genera Phelsuma, Lygodactylus, and Gecko- tacular since they preserve, in high definition, the three lepis have been preserved in Madagascan copal. dimensionality of ancient organisms. To date, fossil re- The study of lizards in amber has been facilitated mains of squamates have been found in six amber de- by the use of X-rays and High-Resolution X-ray com- posits around the world (Daza et al., 2016). Examples puted tomography (HRCT; Polcyn et al., 2002; Daza et include the oldest reptile in amber (Baabdasaurus xe- al., 2013; Castañeda et al., 2014; Sherratt et al., 2015; nurus) from the Early Cretaceous of Lebanon (Arnold et Daza et al., 2016), allowing the rendering of the skele- al., 2002); some scales attributable to a squamate from ton without distortion, in addition to providing incredi- the Albian of France (Perrichot and Néraudeau, 2005); ble integumentary detail. As part of an ongoing research 14 fossil squamates from the mid-Cretaceous of Myan- project, we examined all available gecko specimens in mar, including members with affinities to Iguania, Gek- Miocene amber from Hispaniola preserved in amber us- kota, Scincoidea, Anguimorpha, and Ophidia (Arnold & ing HRCT. One specimen was revealed to be neither a Poinar, 2008; Daza et al., 2016; Fontanarrosa et al., 2018; Sphaerodactylus nor embedded in Miocene amber. The Daza et al., in press; Xing et al., 2018); a gekkotan and specimen was scanned at the Center for Nanoscale Sys- numerous lacertids in Baltic amber (Succinilacerta suc- tems, Harvard University using a Nikon (Metris) X-Tek cinea, Böhme & Weitschat, 1998; Borsuk-Białynicka et HMXST 225 scanner with a molybdenum target at 70kV, al., 1999; Yantarogekko balticus, Bauer et al., 2005; see 135 μA, 1000 ms exposure, 3143 projections, 0.1° rota- also Černaňský & Augé, 2013); and many lizards from tion step, and no filter. The reconstructed voxel size for the Miocene deposits of Mexico and Hispaniola classified the particular specimen was 14.251 μm. The original data in the genus Anolis (A. electrum, Lazell, 1965; Rieppel, set has been archived and is available to the public at Mor- 1980; de Queiroz et al., 1998; Polcyn et al., 2002; Castañe- phosource (https://www.morphosource.org/Detail/ProjectDetail/ da et al., 2014; Sherratt et al., 2015) and Sphaerodactylus Show/project_id/545). Additional specimens for compar- (S. dommeli, Böhme, 1984; S. ciguapa, Daza & Bauer, ison were scanned at UTCT | The University of Texas 2012). Copal specimens have received relatively less High-Resolution CT Facility in a Xradia – Zeiss ma- attention and were reviewed in Broschinski & Kohring chine. The specimens were scanned with a 4X objective,

Received: 04.07.2018 Corresponding editor: R. Peters Accepted: 13.09.2018 Published: 01.11.2018 © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

72 Juan D. Daza et al.

Fig. 1. Specimen ZFMK 94000, in dorsal view. Scale bar equals 5 mm.

70kV/10W using variable parameters. These specimens performed using Avizo Lite 9.5.0 (© FEI SAS, Thermo are part of a large data base of skull Micro-CT that in- Fisher Scientific, 2018). cludes nearly all gekkotan genera (Aaron M. Bauer digi- The specimen in question, from the Alexander Koe- tal collection). All post- processing of the scan data was nig Research Museum (ZFMK 94000, Fig. 1), had been obtained by the museum sponsoring society (Alexan- der-Koenig-Gesellschaft) in November 2012 under the assumption that it was a piece of Dominican amber with a Sphaerodactylus (Gekkota: Sphaerodactylidae) inclu- sion. Although the size and overall appearance is con- sistent with that of these miniaturized geckos (Daza et al. 2008), a more thorough analysis of this material and comparison with the Micro-CT data base of gekkotans indicated that this specimen is a Madagascan clawless gecko of the genus Ebenavia in the family Gekkonidae. Morphological data indicates that the specimen is a sub- fossil, and that the resin is copal, not amber. Copal from Madagascar is botanically assigned to the fabacean species Hymenaea verrucosa (Penney et al., 2005). Copal can be differentiated from mature resins, such as amber, with Raman spectroscopic analyses, showing more intense bands at around 1640 cm−1 due to more stretching vibrations of the v(C=C) attributed to the olefinic group (C=CH2; Winkler et al., 2001). Thermal analyses have also been used to characterize resins; copal from Madagascar may be differentiated from amber and other copal resins in reaching a peak in differential thermogravimetric analysis at 384 °C, while Colombian copal and amber from other localities peaks at 400 °C or more (Ragazzi et al., 2003). The age of copal resins may be only a few hundred to up to four million years old. Fig. 2. Distributional map of Ebenavia species. Colors follow Some resins from Madagascar have been dated using car- Hawlitschek et al. (2018). Additional localities for E. mainti- bon dating analyses to be as young as just a few decades mainty taken from Nussbaum and Raxworthy (1998). (Poinar, 1999; Bosselaers et al., 2010). Other estimates

Bonn zoological Bulletin 67 (2): 71–77 ©ZFMK © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

Miniature gecko in resin 73

Fig. 3. Gecko in copal (Ebenavia boettgeri, ZFMK 94000) A. right lateral view, B. dorsal view; C. ventral view; D. left lateral view indicating the major bones. Abbreviations c#, cervical vertebrae #, l#, left toe #, r#, right toe #, t#, thoracic vertebrae #. for the age of Madagascan copal include a range from (amber yields a sooty odor). 2) Under a UV lamp the Holocene to Recent (10,000–100 y; Schlüter & Gnielins- piece did not show any color change (rather than emitting ki, 1987; Lourenço, 1996; Winkler et al., 2001). In this a bluish glow, as does amber). study, we confirmed that the specimen is embedded in Morphological comparisons considering members of copal based on the morphological similarities with mod- nearly all described gekkotan genera indicate that Ebe- ern species, and some simple tests on the resin: 1) A hot navia shares most morphological characters with ZFMK needle was pushed into the piece, causing rapid melting 94000. The genus occurs on Madagascar and satellite at the point of insertion (rather than slow melting expect- islands, Pemba Island, Grand Comoro, Mohéli, An- ed in amber); the melting resin released a mild fragrance jouan, Mayote, Nosy Bé, Nosy Komba, Île Sainte-Ma-

Bonn zoological Bulletin 67 (2): 71–77 ©ZFMK © Biodiversity Heritage Library, http://www.biodiversitylibrary.org/; www.zobodat.at

74 Juan D. Daza et al.

Fig. 4. HRCT of the skulls of three geckos. Sphaerodactylidae: A. Sphaerodactylus semasiops (MCZ R-55766); Gekkonidae: B. Ebenavia boettgeri (ZFMK 94000), and C. Ebenavia boettgeri (CAS 66195). rie (Nosy Boraha), Nosy Mangabe, and Île aux Prunes E. robusta, E. safari, E. tuelinae; Hawlitschek et al., (Nosy Alañaña), as well as Mauritius (Ramanamanjato 2018, Fig. 2). Copal deposits in Madagascar are concen- et al., 2002; Hawlitschek et al., 2017, 2018; Uetz et al., trated in the northern part of the island (i.e., Cap D’Am- 2018). Until recently Ebenavia included only two species bre and the Sava Region, Geirnaert 2002), which is com- (E. maintimainty and E. inunguis). Ebenavia maintimain- patible with the distribution of E. safari and E. boettgeri ty has a restricted range, being found in Toliara Province (Hawlitschek et al., 2018). in southwestern Madagascar (Nussbaum & Raxworthy, The specimen is embedded in a cone-shaped piece of 1998), while the more widespread E. inunguis was re- orange resin (Fig. 1). The preservation is exceptional, cently split into four new species (viz., E. boettgeri, conserving the complete anterior half of the body. It ap-

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Fig. 5. Lateral view of the snout of ZFMK 94000, inset shows the separation between the rostral scale and the nostril. pears desiccated, but the skeleton is in perfect condition, the estimated SVL of the copal specimen is 34.8–37.8 including the skull, vertebral column (all six cervical and mm. The estimated size matches several species of Ebe- 14 thoracic vertebrae), ribs, pectoral girdle and forelimbs navia, although it greatly exceeds the adult size range of (Figs 1, 3). The skull is intact, with the exception of the E. maintimainty (21–24 mm; Nussbaum & Raxworthy, anterior portion of the left maxillary bone, which appears 1998). damaged, and both sclerotic rings, which are collapsed. The specimen in copal was compared to similar- Even fine details of the skeleton are visible (e.g., small ly sized, formalin-fixed, ethanol preserved specimens sesamoids in the elbow; Fig. 3). Although having an in- of E. boettgeri from St. Marie (Fig. 4) and E. robusta tact skeleton is not necessarily an indication of its young (ZSM296/2010; Hawlitschek et al., 2018). Shared traits geological age (for example, a Mesozoic gecko in amber with Ebenavia include a small premaxilla with a short exhibits a near pristine skeleton, Daza et al., 2016), the ascending nasal process (long in Sphaerodactylus); fused skeleton typically exhibits multiple fractures in the ma- nasals (unfused in Sphaerodactylus); frontal broad with jority of Miocene Sphaerodactylus from Hispaniola. Us- flat dorsal surface (narrow and convex in Sphaerodacty- ing two X-rays from three ethanol preserved specimens lus); quadrate more or less straight with a slightly convex of Ebenavia boettgeri (CAS 66195 [male, based on the conch (curved and extremely convex conch in Sphaero- presence of cloacal bones], CAS 66196 [gravid female dactylus); high number of foramina in the maxillary fa- with 2 eggs], 16º 54' 37.08" S, 49º 54' 40.716" E, St. Ma- cial process (fewer foramina in Sphaerodactylus); high, rie, and USNM 495825 25° 01' 12.0" S, 46° 58' 48.0" E discrete splenial (fused to coronoid in Sphaerodactylus); [gravid female with 1 egg]) we were able to determine stapedial foramen absent (present in Sphaerodacty- that the missing portion of the precloacal region (SVL) lus);dentary ending at the level of the coronoid eminence is between 18 and 25% of the SVL. Using these values, (extending beyond the coronoid in Sphaerodactylus); and

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76 Juan D. Daza et al. retroarticular process narrow (broad in Sphaerodactylus). schem Bernstein (Oligozän von Hispaniola, Antillen). Sala- Morphology of the manus is very similar between the mandra 20: 212–220 two genera, both Ebenavia and Sphaerodactylus having Böhme W, Weitschat W (1998) Redescription of the Eocene the same (plesiomorphic) phalangeal formula (2-3-4-5-3) lacertid lizard Nucras succinea Boulenger, 1917 from Baltic amber and its allocation to Succinilacerta n. gen. Mitteilun- and similar relative length of toes, from largest to small- gen aus dem Geologisch-Paläontologischen Institut der Uni- est III>IV>II>V>I. versität Hamburg 81: 203–222 The copal gecko is clearly differentiated from E. main- Borsuk-Białynicka M, Lubka M, Böhme W (1999) A lizard timainty. Head length in the E. inunguis group is 9.2– from Baltic amber (Eocene) and the ancestry of the crown 9.5 mm (~9.5 in the copal gecko and between 5.4–5.9 group lacertids. Acta Paleontologica Polonica 44: 349–382 in E. maintimainty), dorsal scales are partially keeled Bosselaers J, Dierick M, Cnudde V, Masschaele B, Van Hoore- beke L, Jacobs P (2010) High-resolution X-ray computed to- in the E. inunguis group and the copal gecko (vs. fully mography of an extant new Donuea (Araneae: Liocranidae) keeled in E. maintimainty), and the rostral scale is broad species in Madagascan copal. Zootaxa 2427: 25–35 in the E. inunguis group and the copal gecko (vs. narrow Castañeda MdR, Sherratt E, Losos JB (2014) The Mexican in E. maintimainty). Using the key from Hawlitschek et amber anole, Anolis electrum, within a phylogenetic context: al. (2018), we were able to confirm that ZFMK 94000 implications for the origins of Caribbean anoles. Zoological has the rostral scale separated from the nostril (Fig. 5), Journal of the Linnean Society 172: 133–144 Černaňský A, Augé ML (2013) New species of the genus Ple- which is a character that definesEbenavia boettgeri. This siolacerta (Squamata: Lacertidae) from the Upper Oligocene identification is compatible with the fact that Madagas- (MP28) of Southern Germany and a revision of the type spe- can copal mines are only found in the distribution range cies Plesiolacerta lydekkeri. Palaeontologia 56: 79–94 of E. safari and E. boettgeri. Daza JD, Abdala V, Thomas R, Bauer AM (2008) Skull anat- Even if the gecko in copal is potentially less than sev- omy of the miniaturized gecko Sphaerodactylus roosevelti eral hundred years old, the material provides an historical (Squamata: Gekkota). Journal of Morphology 269: 1340– 1364 record of a living species of Ebenavia in the northeast of Daza JD, Bauer AM (2012) A new amber-embedded sphaero- Madagascar based on the known location of copal de- dactyl gecko from Hispaniola, with comments on the mor- posits (Geirnaert, 2002). The North of Madagascar is a phological synapomorphies of the Sphaerodactylidae. Brevi- critical area for understanding the current distribution of ora 529: 1–28 Ebenavia in Madagascar, as ancestral area reconstruc- Daza JD, Bauer AM, Stanley EL, Bolet A, Dickson B, Losos tions may indicate a colonization of northern Madagascar JB (In press) An enigmatic miniaturized and attenuate whole lizard from the Mid-Cretaceous amber of Myanmar. Breviora from the Comoros Islands (Hawlitschek et al., 2017). Daza JD, Bauer AM, Wagner P, Böhme W (2013) A reconsider- ation of Sphaerodactylus dommeli Böhme, 1984 (Squamata: Acknowledgements. We thank Morris Flecks for taking the Gekkota: Sphaerodactylidae), a Miocene lizard in amber. photograph of the specimen in copal. We also thank Emma Journal of Zoological Systematics and Evolutionary Re- Sherratt (The University of Adelaide), Jessie Maisano and search 51: 55–63 Matt Colbert (UT|CT, The University of Texas at Austin) for Daza JD, Stanley EL, Wagner P, Bauer AM, Grimaldi DA assistance with the HRCT. We thank Rebecca Laver and two (2016) Mid-Cretaceous amber fossils illuminate the past di- anonymous reviewers for comments on the manuscript. The versity of tropical lizards. Science Advances 2: e1501080 Department of Biological Sciences sponsored Jordan P. Hun- de Queiroz K, Chu L-R, Losos JB (1998) A second Anolis liz- ziker to present partial results of this project at The Joint Meet- ard in Dominican amber and the systematics and ecological ing of Ichthyologists and Herpetologists (JMIH) in Austin in morphology of Dominican amber anoles. American Museum 2017. Juan D. Daza received funding from NSF DEB 1657648 Novitates 3249: 1–23 and the Biological Sciences Program at Sam Houston State Fontanarrosa G, Daza JD, Abdala V (2018) Cretaceous fossil University. Aaron M. Bauer received funding from NSF DEB gecko hand reveals a strikingly modern scansorial morpholo- 1555968 and 1556585, and the Gerald M. Lemole Endowed gy: Qualitative and biometric analysis of an amber-preserved Chair Funds. PW is grateful to Jürgen Velten for an ongoing lizard hand. Cretaceous Research 84: 120–133 cooperation in amber research. Geirnaert E (2002) L`ambre – miel de fortune et mémoire de vie. Les Editions du Piat, Saint-Julien-du-Pinet Glaw F, Vences M (2006) Field guide to the amphibians and rd REFERENCES reptiles of Madagascar. 3 edition. Vences & Glaw Verlag GbR, Munich Arnold EN, Azar D, Ineich I, Nel A (2002) The oldest reptile in Hawlitschek O, Toussaint EFA, Gehring PS, Ratsoavina FM, amber: a 120-million-year-old lizard from Lebanon. Journal Cole N, Crottini A, Nopper J, Lam AW, Vences M, Glaw F of Zoology 258: 7–10 (2017) Gecko phylogeography in the Western Indian Ocean Arnold EN, Poinar G. (2008) A 100 million year old gecko with region: the oldest clade of Ebenavia inunguis lives on the sophisticated adhesive toe pads, preserved in amber from youngest island. Journal of Biogeography 44: 409–420 Myanmar. Zootaxa 1847: 62–68 Hawlitschek O, Scherz MD, Ruthensteiner B, Crottini A, Glaw Bauer AM, Böhme W, Weitschat W (2005) An early Eocene F. 2018. Computational molecular species delimitation and gecko from Baltic amber and its implications for the evo- taxonomic revision of the gecko genus Ebenavia Boettger, lution of gecko adhesion. Journal of Zoology 265: 327–332 1878. The Science of Nature 105: 1–21 Böhme W (1984) Erstfund eines fossilien Kugelfingergeckos Lazell Jr J (1965) An Anolis (Sauria, Iguanidae) in amber. Jour- (Sauria: Gekkonidae: Sphaerodactylinae) aus Dominikani- nal of Paleontology 39: 379–382

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Lourenço WR (1996) Premier cas connu d’un sub-fossile de biogeographical transition zone in southeastern Madagascar. scorpion dans le copal de Madagascar. Comptes Rendus de Biodiversity and Conservation 11: 1791–1807 l’Académie des Sciences, Paris Series IIa 323: 889–891 Rieppel O (1980) Green anole in Dominican amber. Nature Nussbaum RA, Raxworthy CJ (1998) Revision of the genus 286: 486-487 Ebenavia Boettger (Reptilia: Squamata: Gekkonidae). Her- Schlüter T, Gnielinski Fv (1987) The East African copal. Its petologica 54: 18–34 geological, stratigraphic, palaeontologic significance and Penney D., Ono H, Selden PA (2005) A new synonymy for comparison with fossil resins of similar age. National Muse- the Madagascan copal spider fauna (Araneae, Selenopidae). um of Tanzania Occasional Paper, Dar es Salaam, Tanzania Journal of Afrotropical Zoology 2: 41–44 8: 1–32 Perrichot V, Néraudeau D (2005) Reptile skin remains in the Sherratt E, Castañeda MdR, Garwood RJ, Mahler DL, Sanger TJ, Herrel A, Losos JB (2015) Amber fossils demonstrate Cretaceous amber of France. Comptes Rendus Palevol 4: deep-time stability of Caribbean lizard communities. Pro- 47–51 ceedings of the National Academy of Sciences of the United Poinar GOJ (1999) Cenozoic fauna and flora in amber.Estudios States 112: 9961–9966 del Museo Ciencias Naturales de Álava 14: 151–154 Uetz P, Freed P, Database JHTR (2018) The reptile database. Polcyn M, Rogers IJ, Kobayashi Y, Jacobs L (2002) Computed Online at http://www.reptile-database.org/ (last access: July tomography of an Anolis lizard in Dominican amber: syste- 2, 2018) matic, taphonomic, biogeographic, and evolutionary implica- Winkler W, Kirchner ECh, Asenbaum A, Musso M (2001) A tions. Palaeontologia Electronica 5: 1–13 Raman spectroscopic approach to the maturation process of Ragazzi, E. Roghi G., Giaretta A., Gianolla P (2003) Classifi- fossil resins. Journal of Raman Spectroscopy 32: 59–63 cation of amber based on thermal analysis. Thermochimica Xing LD, Caldwell MW, Chen R, Nydam RL, Palci A, Simões Acta 404: 43–54 TR, McKellar RC, Lee MSY, Liu Y, Shi HL, Wang K, Bai Ramanamanjato J-B, Mcintyre PB, Nussbaum RA (2002) Rep- M (2018) A Mid-Cretaceous embryonic-to-neonate snake in tile, amphibian, and lemur diversity of the Malahelo Forest, a amber from myanmar. Science Advances 4: eaat5042